A fluid reservoir regulator with a membrane of this type is known from U.S. Pat. No. 4,396,032. The arrangement described in this document requires a large volume of incompressible fluid and does not permit easy changing of the valve seat, this changing requiring an emptying and then a refilling with the incompressible fluid.
Regulators have also been proposed using in place and instead of the flexible wall, a porous wall, this latter approach having however the risk of loss of fluid and in particular for divers in cold water, the drawbacks of penetration of the water into the fluid reserve and as a result risk of seizure of the movable members of the regulator and blocking of the porous wall by ice crystals.